Thorium is a naturally occurring radioactive element, represented by the symbol Th and atomic number 90. It is silvery-white in color and is found in small amounts in various minerals, such as monazite and thorite. Thorium is considered a potential alternative to uranium for nuclear fuel due to its abundance and ability to produce energy through nuclear fission. When used in nuclear reactors, thorium can be converted into uranium-233, which is fissile and can sustain a nuclear reaction. This process is seen as safer and more efficient than traditional nuclear fuels. Additionally, thorium produces less long-lived radioactive waste compared to uranium.